Starting arrangement for internal combustion engines



March 21, 1939. CALLSEN' ET 2,151,463

STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Filed March 17, 1937 5 Sheets-Sheet 1 i I I l i as l II I r 31 I \I [ll/142w MarchZl, 1939. A. CALLSE-N ET AL STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Filed March 17, 1937 '5 Sheets-Sheet 2 A. CALLSEN ET AL 2,151,463

STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES March 21, 1939.

Filed March 17, 193" 5 Sheets-Sheet 3 March 21, 1939. A, LSEN ET M u 2,151,463

STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Filed March 17, 1937 5 Sheets-Shet 4 March 21, 1939. A. CALLSEN ET AL 2,151,463

STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Fild March 1'7, 193'? 5 Sheets-Sheet 5 these parts; it also comprises an abutment'plate Patented Mar. 21, 1939 UNITED STATES STARTING ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Albert. Callsen, Stuttgart-Botnang, and Adolf 'Weiss, Marbach-on-the-Neckar, Germany, assignors to Robert Bosch Gesellsc'naft mit beschriinkter' Haftung Application March 17, 1937, Serial No. 131,472 In Germany March 27, 1936 I 13 Claims.

The present invention relates to a starting arrangement for internal combustion engines of the type in which a pinion connected by a. clutch to the starter shaft is brought into and out of mesh with a driven element by an axial displacement.

In starting arrangements of this type it often occurs that the coupling element, such as the pinion, is moved back along its threadedrspindle too soon, and in consequence comes too soon out of mesh.

According to the present invention a retaining element is provided for 'the coupling element, such as a pinion which is directly or indirectly released by a control element.

The invention is more particularly described in the accompanying drawings in which:-

Figure 1 is a. sectional elevation of one form of construction.

Figure 2 is a similar view with the parts in another position.

Figure 3 is a sectional elevation of an alternative form of construction.

Figure 4 is a view similar to Figure 3 with the parts in another position. a

Figure 5 shows diagrammatically the circuit of the starting devices.

Figure 6 is an enlarged fragmentary view partly in section, of one end of the starter device illustrated in Figs. 1 and 2.

An electric starting motor III has its armature shaft ll extended, and is provided at the end of this shaft with a third bearing. A threaded sleeve I2 is freely rotatable on this shaft, and is provided with two threadings l3, M. A pinion I5 is mounted on the threading l3,'whilst an abutment nut I6 is mounted on the threading H, and bears against the element of a plate.

clutch. i

The plate clutch consists of the aforesaid nut,

I6, a drum l1 keyed to the armature shaft, and

a plurality of friction discs l8 disposed between l9 and a spring abutment 20. The drum I1 is of such a length that it extends over the friction discs.

The control element 2| consists of-a bolt 23 secured sto a rod 22. This rod is guided through the hollow armature shaft 'll of the starting motor, and extends from the end thereof opposite the pinion i5, and is at this end provided with an armature 24 of an electromagnet 25,

which simultaneouslyacts as a'switch, which electromagnet 25 is adapted to draw the rod 22 in and out of the armature shaft when its circuit is completed.

which is mounted on the rod 22 extends through a longitudinal slot 21 in the hollow armature shaft, and lies, 'as has already been indicated, behind the nut 16 to displace this against-a stop flange 28 on the threaded sleeve l2.

Between this stop flange 28 and a flange on the nut IS, a spring 29 is disposed, which tends to. press the nut against the clutch plates. The slots 21 are of such length that when the rod 22 is drawn back, the bolt 23 can move as far as the abutment 20 of the friction discs, so that the abutment or pressure plate l9, which is thicker than this bolt, comes to rest against abutment 20.

At the outer end of the sleeve I2, aflange 30 is provided to which is secured a spring coupling element 3|. This spring coupling element is so disposed that it engages between a pair of the teeth of the pinion when this is meshing with the toothed ring 32 on the engine fly-wheel. The flange 30 and the sleeve l2 are mounted on the flanged end 33 of shaft-ll I A switch element 34 is disposed above the pinion l5, which switch is closed when this pinion is fully meshed with the toothed ring on the fly-wheel. This switch is disposed in the circuit a of the electromagnet 25.

connected in parallel with motor switch H4, to.

one terminal of the electric starter motor ill, the other-terminal of which is grounded. One contact of switch 34 is grounded and the other contact is connected to one end of the electromagnet coil 25, which controls electromagnetic switch I H, the other end of said coil being connected to the circuit between switches Ill and I ll.

The operationof the device is as follows:

In order to start the engine, the driver switches on the starting motor In 'by closing push-button or starter switch'll2 and-this in turn operates electromagnetic switch III to close the circuit to'the electric motor 10 through resistance H3. The threaded sleeve l2 will be turned by the shaft H only howevergthrough the, friction existing between the flanged element 33 and this sleeve 12. ,The pinion mounted on this sleeve will then screw up along its threading due to its inertia, and when it engages against the flange 30 the spring coupling 3| will snap between a pair of its teeth, and simultaneously therewith the switch 34 is closed, closing the circuit of electromagnet 25, whereby the motor switch II] is closed to bridge or short-circuit resistance H3, and consequently the starting motor is given its full voltage. The magnet 25 draws the rod 22 with the bolt 23 back into the position shown in Figure 2, and thus releases the nut ll, so that this can now screw up against the friction discs and become displaced with the friction discs until arrested by the abutment II. The friction disc coupling. is then fully operative as a power coupling, and can transmit full torque on the starting motor.

Should, during the starting period, the internal combustion engine momentarily accelerate, the pinion I i will not come out of mesh, because it is held by the locking element 3| As soon however, as the engine is fully started the automatic release of the clutch takes place and the sleeve l2 catches up with the armature shaft. The pinion is still however, not yet put out of mesh. This will only occur when the driver breaks the circuit of the starting motor, and with it the circuit of the electromagnet. When the circuit of the electromagnet is open the spring 26 will press the rod 22 against the nut Ii, and also the sleeve i! by means of the abutment flange 28 against the flange element 33. By this means, the friction between the starter shaft II and the sleeve I! on the flange 33 has so increased with the resistance of the locking element II that the pinion is overcome, with the consequence that this pinion is then tree to come out oi mesh. In order to aid release of the button or locking element Ii from engagement with pinion ii, the flanks of the teeth on the front side or edge of said pinion are beveled as indicated at I! in Fig. 6. By reason of the beveled flanks, the button II is depressed and released as soon as the momentum exerted on the pinion upon overrunning of the motor has reached a. certain amount. I

In this form of construction, the same control element operates the friction disc coupling, and also controls unmeshing of the pinion.

In the second form of construction shown by way of example in Figures 3 and 4, a locking element is provided which is brought into the locking position indirectly by means of the control element, and is also again freed by this control element. As in the first form of construction, the pinion is mounted on a threaded sleeve ll, which is connected to the hollow starter shaft ll through a friction disc clutch 42. The threaded sleeve has two threadings, one for the pinion, and the other for the abutment nut ll 0'! the friction disc coupling, This friction disc coupling comprises in addition to the nut 43 a 46 mounted on the sta'rtershaft 4|, a number of friction discs 41 disposed between the said drum and nut and an abutment 48 for these friction discs. The sleeve 40 is axially displaceable in two bearings 44 and I. At the inner end of the sleeve a stop flange 40 is provided adapted to engage the abutment 48 when the pinion is "through the starter at the opposite end to the driving side, and is there provided withnn arma-' ture II of an electromagnet in order to displace the mid against the pinion when the circuit or the electro-magnet has completed. The. control rod is adjacent to the end where the pinion is disposed, a flange 58 having a bevelled or conical end surface which, in the position of rest of the starter, and also in the position in which the pinion is out of mesh and the circuit of the electromagnet is open, lies directly behind the hole 52 in which the ball 53 lies. The rod 54 is drawn back into the position of rest by means of a spring 51 disposed between a shoulder 58 on the armature shaft and a flange 68 on this rod. A spring 60 is provided which is adapted to draw back the sleeve into its position of rest when the starting operation is completed. A switch BI is disposed over the pinion in a similar manner to that described with reference to Figures 1 and 2, which switch is operated by the pinion and is in the circuit of the windings of electromagnet controlling the armature 55.

In this second form of construction, the following operations occur at starting:--

0n the closing of the starter switch, the sleeve 40 is turned by the friction discs lightly engaged by reason of the spring ill. The pinion mounted upon that sleeve screws up along it, due to its inertia, and engages with the toothed ring I! of the fly-wheel until it comes up against the annular stop 50. In this position, as shown in Figure 4, the switch 6! is closed by this pinion, and consequently, the electromagnet is excited. The control rod 54 is in consequence displaced against the pressure of the spring 51 and the ball 53 is lifted by reason of the bevelled surface of the flange 56 and is held in this position by this flange. The ball can, in this position of the pinion, move outwards in the sleeve when this pinion lies at the outer end of the threading. The sleeve is displaced against the bearing H by the pinion, as it abuts against the stop 50. In consequence the stop 40 at the inner end of the sleeve moves against the abutment 48 of the-friction disc clutch. This friction disc clutch can then transmit the full torque of the starter, as the friction discs are pressed by the nut 43 with. full force against the abutment. Should the internal combustion engine spurt forward, the pinion is not put out of mesh, as this is prevented by means of the ball. The pinion therefore, is driven by the fly-wheel, but this drive will not be transmitted to the armature, as the clutch acts as a free-wheel.

magnet will the lock formed by the ball I! be released, as the rod N is drawn back by the spring 51, and thus allows the ball to move inwardly. a

We declare that what we claim is:

1. An internal combustion engine starter comprising a prime-mover, means to automatically couple the prime-mover to the engine on operation of the prime-mover, means to lock the coupling between prime-mover and engine during the whole time of operation of the prime-mover,

, and electromagnetically-controlled means to release the coupling between engine and primemover only on cessation of operation of the prime-mover.

2. An internal combustion engine starter comprising an electric motor, an element driven by said motor, means to couple said element to the engine automatically upon closure of the circuit of said electro-motor and an electromagneticallycontrolled lock to'maintain said coupling during the total time of closure of said electric motor circuit.

3. An internal combustion engine starter com- Only when p the driver has opened the circuit of the electrotween said electric motor and the engine automatically engaged on the closing of the circuit of said electric motor, a slipping clutch between said electric motor and the coupling element driven thereby, electromagnetically-controlled means to engage said clutch fully to transmit total torque of said motor only when the coupling is fully engaged, means to lock said coupling when fully engaged, and means to disconnect said locking means only on breaking of the electric motor circuit.

4. An internal combustion engine starter comprising an electric motor, a driving element driven thereby, means to automatically clutch said driv-- ing element to said engine on the closing of said motor circuit, locking means for said driving element, an electromagnetic control means for said locking means, and means to release said locking means on the breaking of the motor circuit.

5. An internal combustion engine starter comprising an electric motor, a driving element driven thereby, means to automatically clutch said driving element to said engine on the closing of said motor circuit, locking means for said driving element, electromagnetic control means for said locking means, a switch controlling said electromagnetic control means, means to close said switch and the circuit of said electro-magnet when said clutch is fully engaged, means to break the circuit of said electro-magnet on the breaking of the motor circuit, and spring means to disconnect said locking means on the breaking of said circuits.

6. An internal combustion engine starter comprising an electric motor, a driving element driven thereby, means to automatically clutch said driving element to said engine on the closing of said motor circuit, locking means for said driving element, electromagnetic-control means for said locking means, a switch controlling said electromagnetic control .means, means to close said switch and the circuit of said electro-magnet when said clutch is fully engaged, means to break the circuit of said electro-magnet on the breakdriving element driven by the electric motor and v said electric motor, means to control said friction clutch, so that it transmits full torque only when the element driven from said electric motor is fully engaged with the engine, and means to release said friction clutch simultaneously with the release of the locking means and the breaking of the circuits of said electric motor, and electro-- magnet.

'7. An internal combustion engine starter com- I prising an 'electric motor, a threaded sleeve driven thereby, a pinion threaded on said sleeve and axially displaceable thereon by reason of its inertia, a toothed starter ring connected to the engine, a friction clutch between the said sleeve and said electric motor, means including an electroprising an electric motor, a coupling element becontrolling said lock, and means to break the circuit of said electromagnet and said motor simultaneously.

8. An internal combustion engine starter comprising an electric motor, a threaded sleeve driven.

thereby, a pinion in threaded engagement with and axially displaceable along said sleeve by reason of its inertia, a friction clutch between said sleeve and said electric motor, automatic torque control means for said clutch whereby the full torque of said electric motor is only transmitted thereby upon full axial displacement of said pinion, locking means between said pinion and said sleeve, a toothed ring on said engine engaged by said pinion when fully displaced axially, an electro-magnet controlling said locking means, a switch controlling the circuit of said electro-magnet and operated by said displaceable pinion, and means to simultaneously break the circuit of said electro-magnet and said electric motor.-

9. An internal combustion engine starter comprising a motor, a threaded shaft driven by said motor, a driving member in threaded engagement with said shaft for axial displacement thereon to automatically engage and disengage said engine,

-and electromagntically-controlled means for preventing disengaging movement of said driving member during operation of said motor.

10. An internal combustion engine starter comprising an electric motor, a threaded shaft driven by said electric motor, a pinion in direct threaded engagement with said shaft for axial displacement thereon to automatically engage and disengage a gear member of an engine to be started, and means for locking said pinion in engagement with said engine gear member until after deenergization' of said electric motor.

11. An internal combustion engine starter comprising an electric motor, a threaded shaft driven by said motor, a clutch between said motor and said shaft, a driving member in threaded engagement with said shaft for axialdisplacement thereon to automatically engage and disengage said engine, and electromagnetically-controlled means for controlling the operation of said clutch and for preventing disengaging movement of said driving member until after de-energization of said electric motor. 1

12.- An internal combustion engine starter com prising a motor, a threaded shaft driven by said I motor, a driving member in threaded engagement with said shaft for axial displacement thereon to automatically engage and disengage said engine, a stop member to lock said driving member in .its engaged position, and electromagnetically controlled means to release said stop member from its locking position.

13. ,An internal combustion engine starter comprising an electric motor, a threaded shaft driven by said electric motor, a driving member in threaded engagement with said shaft for axial displacement thereon to automatically engage and disengage a member of the engine to be started, a stop member to lock said driving member in its engaged position, and electromagnetically-controlled means for preventing release of said stop member from locking position until after de-energization of said electric motor.

men-r causes. snouwnrss. 

